For a long time, lead (and later manganese) compounds have been employed as octane-improving compounds in gasoline. For example, U.S. Pat. No. 1,592,953 disclosed the use of tetraethyl lead as an antiknock (octane improving) additive for gasoline in the early 1920's. Other antiknock compounds are also known.
Recently, the Environmental Protection Agency has banned use of lead- and manganese-based antiknock compounds in certain types of gasoline. However, since higher compression engines (which require higher octane fuel) are more efficient, the need for higher octane gasoline remains. One way of increasing octane quality without lead or manganese compound is through the use of ashless antiknock compounds. For example, the antiknock activity and aniline and some of its derivatives has been known for nearly sixty years. Recently, Hartle and Singerman disclosed use of novel aniline-based antiknocks--orthoazidoanilines--at the March 1980 American Chemistry Society Symposium on Chemistry for Octane Improvement. However, use of these aniline compounds also resulted in a significant increase in NO.sub.x emissions.
A new ashless antiknock compound has now been found that not only improves octane and antiknock properties, but also should not adversely effect NO.sub.x emissions as much as some other antiknock compounds.